Les systèmes cryptographiques à base de courbes elliptiques sont aujourd'hui de plus en plus employés dans les protocoles utilisant la cryptographie à clef publique. Ceci est particulièrement vrai dans le monde de l'embarqué qui est soumis à de fortes contraintes de coût, de ressources et d'efficacité, car la cryptographie à base de courbes elliptiques permet de réduire significativement la taille des clefs utilisées par rapport aux systèmes cryptographiques précédemment employés tels que RSA (Rivest-Shamir-Adleman). Les travaux qui suivent décrivent dans un premier temps l'implantation efficace et sécurisée de la cryptographie à base de courbes elliptiques sur des composants embarqués, en particulier des cartes à puce. La sécurisation de ces implantations nécessite de prendre en compte les attaques physiques dont un composant embarqué peut être la cible. Ces attaques incluent notamment les analyses par canaux auxiliaires qui consistent à observer le comportement d'un composant pendant qu'il manipule une valeur secrète pour en déduire de l'information sur celle-ci, et les analyses par faute dans lesquelles un attaquant peut perturber un composant dans le même but.Dans la seconde partie de ce mémoire de thèse, nous étudions ces attaques et leurs implications concernant l'implantation des systèmes cryptographiques à clef publique les plus répandus. De nouvelles méthodes d'analyse et de nouvelles contre-mesures sont en particulier proposées. Une étude spécifique de certaines attaques appliquées à l'algorithme de chiffrement par bloc AES est également présentée. / Elliptic curve based cryptosystems are nowadays increasingly used in protocols involving public-key cryptography. This is particularly true in the context of embedded devices which is subject to strong cost, resources, and efficiency constraints, since elliptic curve cryptography requires significantly smaller key sizes compared to other commonly used cryptosystems such as RSA.The following study focuses in a first time on secure and efficient implementation of elliptic curve cryptography in embedded devices, especially smart cards. Designing secure implementations requires to take into account physical attacks which can target embedded devices. These attacks include in particular side-channel analysis which may infer information on a secret key manipulated by a component by monitoring how it interacts with its environment, and fault analysis in which an adversary can disturb the normal functioning of a device in the same goal.In the second part of this thesis, we study these attacks and their impact on the implementation of the most used public-key cryptosystems. In particular, we propose new analysis techniques and new countermeasures for these cryptosystems, together with specific attacks on the AES block cipher.

Ce travail examine les changements dans l'organisation de Hattuša, une ville de l'âge du bronze au nord de l'Anatolie centrale, lorsqu'elle devient la capitale des Hittites. Cette étude pose de façon innovatrice le problème de l'organisation de la cité-état (1950-1750 av. J.-C.) et celle de la capitale de royaume (1700-1200 av. J.-C.), en regardant les liens entre organisation politique et réalité urbaine à travers une analyse diachronique, reproductible et multiscalaire du principal quartier d'habitation de la ville, la Westterrasse. L'analyse chronologique démontre que la phase la mieux attestée de la Westterrasse ne date pas des XIVe-XIIIe siècles av. J.-C., comme il est communément admis, mais des XVIe-XVe siècles av.J.-C. Les rapports entre les bâtiments, les voies de circulation et le système d'évacuation des eaux illustrent la planification de la Westterrasse, la gestion des aménagements collectifs, de l'habitat privé et souligne la médiation nécessaire pour leur cohabitation. La répartition des petits objets révèle les profils principaux de la population de la Westterrasse, qui sont replacés dans le contexte politique du devenir de la capitale hittite. / This study investigates changes in the organisation of the Bronze Age city of Hattuša (North Central Anatolia), during the time the site became the capital of the Hittites. Interweaving a diachronic, reproducible and multi-scalar analysis of the main living quarter of the city (the so-called Westterrasse), this study enables an innovative exploration of the organisation of the city-state (1950-1750 BCE) and capital of the Hittite kingdom (1700-1200 BCE), by attending to the links between politics and urban space. The chronological analysis demonstrates that the best-recovered phase of the Westterrasse dates to the 16th-15th century and not to the 14th-13th century as previously assumed. The study of the buildings, streets and sewage system indicate a high degree of planning for the Westterrasse with careful management of both public infrastructure and private dwelling, which underline the mediation necessary for their cohabitation. The insights afforded by examination of the distribution of finds reveal the broad contours of the population of the Westterrasse, as they are situated in the political context of the future Hittite capital.

Magister Artium (Psychology) - MA(Psych) / The fall of apartheid and the rise of democracy have brought assessment issues in multicultural societies to the forefront in South Africa. The rise of multicultural assessment demands the development of tests that are culturally relevant to enhance fair testing practices, and issues of bias and equivalence of tests become increasingly important. This study forms part of a larger project titled the Additive Bilingual Education Project (ABLE). The Woodcock Munoz Language Survey (WMLS) was specifically selected to evaluate the language aims in the project, and was adapted from English to isiXhosa. Previous research has indicated that one of the scales in the adapted isiXhosa version of the WMLS, namely the Picture Vocabulary Scale (PV), displays some item bias, or differential item functioning (DIF), across rural and urban isiXhosa learners. Research has also indicated that differences in dialects can have an impact on test takers’ scores. It is therefore essential to explore the structural equivalence of the adapted isiXhosa version of the WMLS on the PV scale across rural and urban isiXhosa learners, and to ascertain whether DIF is affecting the extent to which the same construct is measured across both groups. The results contribute to establishing the scalar equivalence of the adapted isiXhosa version of the WMLS across rural and urban isiXhosa-speaking learners. Secondary Data Analysis (SDA) was employed because this allowed the researcher to re-analyse the existing data in order to further evaluate construct equivalence. The sample of the larger study consisted of 260 learners, both male and female, selected from a population of Grade 6 and 7 learners attending schools in the Eastern Cape. The data was analysed by using the statistical programme Comprehensive Exploratory Factor Analysis (CEFA) and the Statistical Package for Social Sciences (SPSS). Exploratory factor analysis and the Tucker’s phi coefficient were used. The results indicated distinct factor loadings for both groups, but slight differences were observed which raised concerns about construct equivalence. Scatter plots were employed to investigate further, which also gave cause for concern. It was therefore concluded that construct equivalence was only partially attained. In addition, the Cronbach’s Alpha per factor was calculated, showing that internal consistency was displayed only for Factor 1 and not for Factor 2 for the rural group, or both factors for the urban group. Scalar equivalence across the two groups must therefore be explored further.

Magister Psychologiae - MPsych / In many countries defined by multilingualism, language has been identified as a great influence during psychological and educational testing. In South Africa (SA), factors such as changes in policies and social inequalities also influence testing. Literature supports the translation and adaptation of tests used in such contexts in order to avoid bias caused by language. Different language versions of tests then need to be evaluated for equivalence, to ensure that scores across the different language versions have the same meaning. Differences in dialects may also impact on the results of such tests.Results of an isiXhosa version of the Woodcock Muñoz Language Survey (WMLS),which is a test used to measure isiXhosa learners’ language proficiency, show significant mean score differences on the test scores across rural and urban firstlanguage speakers of isiXhosa. These results have indicated a possible problem regarding rural and urban dialects during testing. This thesis evaluates the item bias of the subtests in this version of the WMLS across rural and urban isiXhosa learners. This was accomplished by evaluating the reliability and item characteristics for group differences, and by evaluating differential item functioning across these two groups on the subtests of the WMLS. The sample in this thesis comprised of 260 isiXhosa learners from the Eastern Cape Province in grade 6 and grade 7, both males and females. This sample was collected in two phases: (1) secondary data from 49 rural and 133 urban isiXhosa learners was included in the sample; (2) adding to the secondary data, a primary data collection from 78 rural isiXhosa learners was made to equalise the two sample groups. All ethical considerations were included in this thesis. The results were surprising and unexpected. Two of the subtests in the WMLS showed evidence of scalar equivalence as only a few items were identified as problematic. However, two of the subtests demonstrated more problematic items. These results mean that two subtests of the WMLS that demonstrated evidence of scalar equivalence can be used to measure the construct of language proficiency, while the other two sub-tests that showed problematic items need to be further investigated, as the responses given by learners on these items seem to be determined by their group membership and not by their ability.

The influence of stratification on the structure of turbulent methane/air combustion is investigated using experimental data from laboratory scale burners: a weakly turbulent slot burner, and a higher turbulence co-annular swirl burner. The degree of stratification can be controlled independently of the overall fuel/air flow rate. The resulting measurements of scalar and velocity fields provide detailed test cases for existing and emerging turbulent flame models, covering a range of u'/sL from 1 to 10, turbulence intensities from 5% to 60%, and stratification ratios from 1 to 3. Simultaneous Rayleigh/Raman/CO-LIF measurements of temperature and major species concentrations - CH4, CO2, CO, H2, H2O and O2 - along a line are used to investigate the structure of a series of flames in both the slot and swirl burners. Concurrent cross-planar OH-PLIF allows thermal gradients to be angle corrected to their three-dimensional values. Finally, non-reacting and reacting velocity fields complete the flame database. The behavior of major species concentrations in the slot and swirl burner with respect to temperature is found to agree well on the mean with unstrained premixed laminar flame calculations. Scalar means conditioned on stoichiometry also show good agreement, aside from hydrogen which is enhanced under stratified conditions. Surface density function and scalar dissipation are lower than calculated values in all cases, suggesting that turbulence-induced thickening dominates the effect of increased strain. Metrics commonly used to derive flame surface density (FSD) were investigated. FSD may be determined using a statistical method based on measurements of temperature and its gradient, or a geometric method based on 2D temperature or LIF imaging. A third metric, an extension of the geometric method, is proposed. Good agreement is observed between the three metrics. The current database provides the first detailed high resolution scalar measurements for premixed and stratified flames. The data analysis provides insight into the physics of stratification: for the flames considered, the effects of stratification appear to be surprisingly small compared to those of turbulence, even at significant stratification ratios. The datasets provide a means of validating current and future computational turbulent combustion models.

La pollution atmosphérique et ses conséquences sur la santé et l'environnement constituent un domaine d'étude complexe à cause du nombre de phénomènes physiques mis en jeu. L'objectif de ce travail est d'étudier les principales caractéristiques de l'écoulement et de la dispersion d'un scalaire passif au sein de la canopée urbaine. Pour ce faire, un code numérique a été développé. Il résout les équations de Navier-Stokes dans le cadre d'un écoulement incompressible pour une atmosphère neutre en faisant usage de la méthode de la compressibilité artificielle selon la méthode des volumes finis. Le modèle de Spalart-Allmaras a été utilisé pour la modélisation de la turbulence. La canopée urbaine est explicitement prise en compte et est modélisée par un groupe d'obstacles de forme cubique. Le code fut d'abord testé pour des configurations bidimensionnelles avec un seul et 4 obstacles en configuration alignée selon deux approches : une simulation stationnaire RANS et instationnaire URANS qui reproduit le décrochement tourbillonnaire. La prise en compte du décrochement tourbillonnaire se traduit par une diffusion dans le sillage turbulent du groupe d'obstacles. Les résultats ont été comparés à des mesures expérimentales et d'autres résultats numériques de référence dans la bibliographie et montrent l'amélioration du champ de vitesse moyen par l'approche code fut ensuite testé sur un cas tridimensionnel avec un groupe d'obstacles organisés selon 2 configurations géométriques: alignée et en quinconce. Afin d'éliminer les effets des conditions aux limites, l'écoulement fut calculé sur un volume élémentaire de calcul en utilisant des conditions aux limites périodiques. Deux types de simulations furent réalisés: l'approche RANS classique et la version DDES du modèle de Spalart-Allmaras. L'écoulement obtenu par la DDES améliore de façon significative les résultats par rapport au RANS en comparaison de mesures expérimentales de simulation directe et montrent la bonne potentialité du modèle. La dispersion d'un scalaire passif émis au sein de la canopée fut obtenue sur un domaine plus important comprenant 16 volumes élémentaires par le biais des conditions aux limites périodiques utilisées. Une analyse du champ de concentration a ensuite été réalisée et des comparaisons effectuées en fonction du type de calcul et de la configuration géométrique. / Atmospheric pollution and its impact on health and the environment depend on many physical phenomena, and this makes it a difficult subject to study. The main objective of this work is to investigate the main characteristics of the flow and dispersion of a passive scalar in the urban canopy. Specifically, the urban canopy is simulated by a group of cubical obstacles in a neutrally-buoyant atmospheric boundary layer. A numerical code bas been developed as a tool to aid in this study; flow is computed by solving the Navier-Stokes equations for an incompressible flow, using a finite volume approach, and the method of artificial compressibility. The turbulence is modeled using the method proposed by Spalart and Allmaras. The code was tested first in a 2-D configuration, for flow over a single obstacle, and over a group of 4 obstacles; in both cases two types of simulation were studied: a stationary RANS simulation, and an unsteady RANS (URANS), which reproduced vortex shedding from the obstacles. The explicit inclusion of vortex shedding in the URANS simulation leads to diffusion in the obstacle wakes, and the results compare better with experimental measurements and other published numerical simulations than do those for the RANS simulations. The code was then tested for some 3-D cases consisting of a group of obstacles arrangcd either in aligned or staggered configurations. In order to avoid the influence of boundary conditions, the flow field was simulated using periodic boundary conditions and a small sub-unit from the group of obstacles. Two types of simulation were performed: a classical RANS type calculation and the DDES proposed by Spalart and Allmaras. The results obtained using the ODES agree much more closely with experimental measurements and the results of other numerical simulations than do those obtained using RANS, and indicate the potential of this approach. The dispersion of a passive scalar in the urban canopy was simulated on a much larger domain consisting of 16 of the sub-units used to compute the flow field. The concentration fields were analyzed to show the influence of the geometrical configuration and the type of model.

La « fin de la géographie » constitue un sujet de débats et d’oppositions entre les économistes et lesgéographes. Pourtant, les premiers participent à la reconnaissance du rôle de la géographie par la miseen évidence de l’influence toujours prégnante de la distance géographique sur les comportementsfinanciers. Ainsi, les économistes participent à la construction de cette discipline. Dans cetteperspective, l’objectif de cette thèse est l’intégration des OPCVM européens comme objets d’analysepertinents en géographie de la finance. Elle suppose de s’interroger sur le fonctionnement del’industrie, ses pratiques, sa réglementation. Le point focal mis sur le marché européen des OPCVMpermet de mettre au coeur de l’analyse le processus d’expansion spatiale inhérent à la finance. Si lesprincipes guidant cette expansion trouvent leurs origines dans l’industrie américaine, cette thèsesouligne le rôle actif joué par les États, l’Europe et les acteurs français. La circulation différenciée descapitaux au sein du marché européen révèle la logique multi-scalaire de la finance / The “end of geography” is a disputed and controversial topic among economists and geographers.Nevertheless economists contribute to the recognition of the role of geography by highlighting thepersistently important influence of geographic distance over financial behaviour. In this way they takepart in the construction of the discipline. Seen in this light, the aim of this study is the integration ofEuropean UCITS as a relevant research topic in geography of finance. The study claims to questionthe functioning of the industry, its practices and its regulation. The focus on European markets ofUCITS enables to place the process of geographic expansion in the centre of analysis. If the principlesguiding this expansion find their origins in the US, this study highlights the active role of States,Europe and French actors. Differentiated circulation of capital within European markets reveals themulti-scalar logic of finance.

Orientador: Lucas Catão de Freitas Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-24T12:47:02Z (GMT). No. of bitstreams: 1 Lima_LidianedosSantosMonteiro_D.pdf: 2071234 bytes, checksum: 6370d2ea978f96792562cdc2e2406365 (MD5) Previous issue date: 2014 / Resumo: Nesta tese consideramos uma família de EDPs dissipativas do tipo escalar ativo cujos campos velocidades são acoplados aos escalares através de operadores multiplicadores de Fourier que podem ser de alta ordem. Na primeira parte, provamos boa-colocação global, decaimento de normas Lp, e algumas propriedades de simetria, para dados iniciais no espaço de Lebesgue crítico e sem assumir condição de pequenez. Na segunda parte, introduzimos os espaços de Fourier-Besov-Morrey, o qual parece ser novo na analise de EDPs, com o objetivo de encontrar soluções auto-similares e considerar uma classe maior de acoplamentos e dados iniciais. Condições de pequenez na norma do espaço são assumidas para estes resultados. Além disso, mostramos um resultado de estabilidade assintótica e obtemos uma classe de soluções assintoticamente auto-similares / Abstract: In this thesis we consider a family of dissipative active scalar equations whose velocity fields are coupled by means of multiplier operators that can be of high-order. In the first part, we prove global well-posedness, decay of Lp's norms and some symmetry properties of solutions for initial data in the critical Lebesgue space and without smallness condition. In the second part, we introduce the Fourie-Besov-Morrey spaces, which seems to be new in the analysis of PDEs in order to find self-similar solutions and to consider a larger class of couplings and initial data. Smallness conditions on the norm of the space are assumed for these results. Furthermore, we show an asymptotic stability result and obtain a class of asymptotically self-similar solutions / Doutorado / Matematica / Doutora em Matemática

The goal of this master´s thesis is primarily the theoretical analysis of three-phase inverters and subsequent familiarization of the reader with their detailed practical structure. The first part is devoted to the general definition of the power semiconductor converter as such. The following part describes the principle of three-phase pulse width modulation including the widely used principle of scalar control of induction motors. The second half of the thesis is already focused on the practical design of a three-phase inverter for a 50 kW high-speed induction motor. This section explains the problem of sizing and selecting all of the sub-elements of the inverter based on the parameters specified by the end user of the device.

This thesis deals with a design of an electrical drive for a sliding side door. Goal of the thesis is to design of a frequency converter for an asynchronous motor with a gearbox. In the first part, the power supply for the freqency converter is solved in form of a single phase rectifier. Power section is solved by an integrated module IKC10H60GA manofactured by Infineon. The control board is provided with circuits for communication between the processor and the power section. Auxiliary power supply is designed as a fly - back converter. The drive of the converter is realized by STM32 Nucleo - 64 board. The design of the converter and drive algorithm are described in detail.